In a rare public and personal speech, the queen thanked all those who have sent letters and messages following the death of Inés Zorreguieta, her younger sister.

Argentine born Dutch Queen Maxima on Tuesday paid an emotional tribute to her beloved late younger sister, who was found dead earlier this month in Buenos Aires in a suspected suicide. In a rare public and personal speech – her first public appearance since the death – the queen thanked all those who have sent letters and messages following the death earlier this month of Inés Zorreguieta, her younger sister.

Zorreguieta, 33, had previously suffered from depression and mental illness and was found dead on June 6 at her home in Buenos Aires.

I'm so pleased to be back at work at this centre, which helps so many people suffering from cancer, Maxima, 47, said as she visited a proton therapy centre in Groningen for treating illnesses such as cancer. People who are ill, but who haven't lost hope to recover.

My little, darling, talented sister Inés was sick, she added. She couldn't find joy in anything and she couldn't get better. Our only comfort is that she is finally at peace.

The Dutch queen added the countless letters she had received had been a real help.

I also want to take the opportunity to thank everyone who has sent cards and messages. It's been such a great help. I also want to thank the press for respecting our family's privacy. Thank you, thank you, thank you, she said.

Maxima, who is from Argentina, flew to Buenos Aires with her husband Dutch King Willem-Alexander and their three daughters to attend a private funeral earlier this month. Her spokesperson said at the time she was deeply shocked and devastated to learn of her sister's tragic death.

Despite moving to the Netherlands, Maxima had maintained a close relationship with her sister, 13 years her junior. Inés was the maid of honor at Máxima's wedding as well as a godmother to her youngest daughter, Princess Ariane.

Queen Maxima also has two brothers, Martín and Juan, as well as three half-sisters from her father's first marriage. Máxima's father, Jorge Horacio Zorreguieta, died last year in Buenos Aires at age 89.

Zorreguieta, born in 1984, was a psychologist who once worked for an office on social policies at the president's office. She had also worked for the Social Development Ministry in Buenos Aires province and at a United Nations office in Panama.

She was also known a singer and guitarist, and had previously suffered from depression. She was admitted to a psychiatric clinic in Buenos Aires in 2012, believed to have been suffering from anorexia and paranoia.